Railway signal control system



Aug. 21, 1951 w. H. CLAUS RAILWAY SIGNAL CONTROL SYSTEM Filed Aug. 26, 1947 I INVENTOR. will mH Llaus BY HIS ATTORNEY m m5 mmihw Patented Aug. 21, 1951 RAILWAY SIGNAL CONTROL SYSTEM William H. Claus, Downers Grove, Ill., assignor to The Union Switch and Signal Company,

Swissvale, Pa., a corporation of Pennsylvania Application August 26, 1947, Serial No. 770,650

My invention relates to a railway signal control system, and particularly to a directional control system for signals for a stretch of railway track over which traffic movements are regularly made in both directions.

In a directional control system for signals for governing trafiic movements over a stretch of single railway track which is divided into two blocks for each direction of traffic movements, such, for example, as between consecutive passing sidings, an entering signal for governing trafl'ic movements in a given direction into the single track stretch may be controlled to display aclear indication only if a leaving signal for governing traific movements out of the opposite end of the stretch is displayin a proceed indication, and it is common practice to control the entering signal to indicate stop if any portion of the stretch is occupied by a train moving in the opposite direction, but to control the entering signal to indicate stop if a train moving in the given direction occupies only the first block in advance of the entering signal, and to control the entering signal to display an indication to permit a train moving in the given direction to enter the stretch if the first block in advance of the entering signal is clear while the second block in advance of the enterin signal is occupied by a train moving in the given direction.

One feature of my invention is the provision of means including two polar biased relays for controlling an entering signal for a stretch of single railway track to display three diiferent proceed indications corresponding to three proceed conditions, for governing trafiic movements in a given direction, in addition to the stop indication, as shown in the following tabulation:

N ame oi 5, 5 Indication of Entering Signal g f Signal Stop First block in advance of enter- Red.

ing signal occupied by train moving in the given direction, or any part of single track stretch occupied by train moving in opposite direction. Approach.- First block in advance of enter- Steady yellow. ing signal unoccupied, second block in advance occupied by train moving in given direcon. A d v a n c e Single track stretch unoccupied, Flashing yellow.

Approach. leaving signal at opposite end of single track stretch indicates stop. Clear Single track stretch unoccupied, Green.

leaving signal at opposite end of single track stretch displays a proceed indication.

6 Claims. (01. 246--33) I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention, in which two polar biased code following relays for controlling an entering signal for a stretch of railway track are connected in series with each other, but in opposed relation, so that one of the polar biased relays will close its front contacts in response to current of a given polarity passing through these relays, and the other polar biased relay will close its front contacts in response to current of the opposite polarity, and in which steady current of normal polarity or coded current of reverse polarity is supplied to these relays according as the leaving signal for the opposite end of the stretch of track is controlled to display a proceed or a stop'indication, respectively, while the stretch of track is unoccupied, and steady current of reverse polarity is supplied to these relays when a direction stick relay becomes energized in response to a train moving in the given direction from the first to the second block in advance of the entering signal.

Similar reference characters refer to similar parts in the drawing.

Referring to the drawing, a stretch of single track railway T is shown extending between passing tracks X and Z. In order to simplify the drawing, each track, comprising two parallel series of track rails, is represented by a single line.

Track T is divided by insulated joints 1 into sections ab, b-c and 0-01. Each of these sections is provided with a track circuit including a suitable source of current, such as a battery 8, connected across the rails adjacent one end of the section, and a track relay, designated by the reference character TR. with a distinguishing prefix, connected across the rails adjacent the opposite end of the section.

An entering signal, designated by the reference character IS, located at a, governs trafiic movements to the right, as shown .in the drawing, which I shall assume is the eastbound direction, into the stretch of single track. An intermediate signal, designated by the reference character 38, at b, governs eastbound traffic movements from the first block in advance of signal IS, comprising section a-b, into the second block which comprises sections b-c and 0-11. A leaving signal, designated by the reference character 58, governs eastbound trafiic movements out of the stretch ud of single track. Westbound sig-.

" nals, designated by the reference characters 2S,

4S and 5S correspond to eastbound signals 53, 3S and IS, respectively, and may be controlled similarly to signals SS, 38 and IS. The signals may be of any suitable design, such, for example, as the color light type having a green lamp G, a yellow lamp Y and a red lamp R, as shown in the drawing.

Signal 5S may be controlled by any suitable means such, for example, as a polarized signal relay 5H having slow releasing neutral contacts, in accordance with traific conditions east of signal 58. When relay 5H is energized by current of normal polarity, signal 5S is controlled to display the proceed indication which is known as the clear indication, by means of its green lamp aspect, and when relay SE is energized by current of reverse polarity, signal SS is controlled to display the proceed indication which is known as an approach indication, by means of its yellow lamp aspect.

Signal SS is controlled by a second polarized signal relay 3H having slow releasing neutral contacts, which is energized by current of normal or reverse polarity according as relay 5H is energized or deenergized while block 12-11 is unoccupied. Signal 3S is controlled by relay 3H simllarly to the manner in which signal SS is controlled by relay 5H, as already described.

A slow release direction stick relay 3SR becomes energized in response to a train moving from block a-b into block b-d, while relay 3H is energized, for controlling signal IS to display its approach indication. A repeater relay 3P is controlled by a front contact and a reverse polar contact of relay 3H. A periodically operating device CT, which may be of any of the well-known flasher relay types or of the well-known code transmitting relay type, is controlled by a front contact of relay 3P.

Two polar biased relays of the code following type, designated by the reference characters HB and DB, for controlling signal IS, are connected in series with each other, but in opposed relation, so that relay DB closes its front contacts when current, which I shall assume is of normal polarity and which flows in the direction indicated by the arrow in the symbol for relay DB, is passed through these relays. Relay I-l'B closes its front contacts when current of reverse polarity, flowing in the direction indicated by the arrow in the symbol for relay HB, passes through these relays. Relays DB and HB are energized by steady current of reverse polarity when relay 3SR is energized. When relay 33R is deenersized, relays DB and HB are energized by periodically varied or coded current of reverse polarity, or by steady current of normal polarity, according as relay 31-1 is energized by current of reverse or of normalpolarity, respectively.

A signal control relay BP is controlled by relays DB and HB so that relay BP is energized when either one of the relays DB and HE is energized while the other of these two relays is deenergized, but relay BP is deenergized when relays DB and HB are both .d'eenergized or both energized. A condenser 28 is connected in multiple with the winding of relay BP in order to make this relay slow in releasing.

Signal IS is controlled by relays BP, DB and HB. to display three proceed indications, namely, the clear, advance approach, and approach, as well as the stop indication. The clear, advance approach and approach indications are displayed by the. steady green, flashing yellow and steady.

yellow aspects, respectively, of signal IS.

Having described, in general, the arrangement of the various parts of apparatus embodying my invention, I shall now describe the circuits and operation in detail.

As shown in the drawing, all parts of the apparatus are in the normal condition, that is, the stretch of track shown is unoccupied; each of the signals IS, 3S and SS is displaying the clear indication; relays 3H, 5H, DB and HB are energized by current of normal polarity; relay 3? is energized; and relays 35R, SP and CT are deenergized.

Only a portion of the control circuit for relay 5H is shown, including contact 9 of relay 5TB. Lamp G of signal 5S is lighted by a circuit passing from terminal B of a suitable source of current, through the front point of contact [0 of relay 5H, contact ll of relay 5H closed in the normal position, and lamp G to terminal N of the same source of current.

Relay 3H is energized by current of normal polarity passing from terminal B, through the front point of contact I2 of relay 5H, contacts I3 and M of relays A3TR and 3TR, respectively, winding of relay 3H, and the front point of contact l5 of relay 51-1 to terminal N. With relay 3H energized by current of normal polarity, lamp G of signal 38 is lighted by a circuit which is similar to the circuit previously traced for lamp G of signal 5S.

With relay 3H energized by current of normal polarity, relays DB and HB are energized by current of normal polarity passing from terminal B, through contact l6 of relay 3H, contact I! of relay 3H closed in the normal position, back point of contact 18 of relay 3P, back point of contact [9 of relay 3SR, contact 20 of relay ITR, windings of relays HB and DB, back point of contact 2| of relay 3SR, and the back point of contact 22 of relay 3P to terminal N. With relays DB and HB thus energized by current of normal polarity, the contacts of relay DB are closed at their front points, and the contacts of relay HB remain closed at their back points.

Relay BP is therefore energized by a circuit passing from terminal B, through the back point of contact 16 of relay HB, front point of contact 21 of relay DB, and the winding of relay BP connected in multiple with condenser 28, to terminal N.

Lamp G of signal IS is therefore lighted by a circuit passing from terminal B, through the front point of contact 29 of relay BP, front point of contact 30 of relay DB, back point of contact 3| of relay HB, and lamp G of signal IS to terminal N.

I shall assume that, with apparatus arranged as shown in the drawing, an eastbound train enters block. a-b, deenergizing relay I'I'R. With relay ITR deenergized, relays DB and B]? become deenergized, causing lamp G of signal [S to be extinguished and lamp R to be lighted by a circuit passing from terminal B, through the back point of contact 29 of relay BP, and red lamp R to terminal N.

When the train enters section bc, relay 3H becomes deenergized because of the opening of contact Id of relay 3TR. Since the neutral contacts of relay 3H are slow releasing, contact 34 of this relay remains closed at its front point for a brief period of time, so that relay 3SR becomes energized by its pick-up circuit passing from terminal B, through contact 32 of relay 3TR, front.

becoming energized, closes its contact 33, so that, when contact 34 of relay 3H closes at its back point, relay SSR, which is sloW releasing, remains energized by its stick circuit passing from terminal B, through contact 33 of relay 38R, back point of contact 3% of relay 3H, and the winding of relay SSR, to terminal N.

Relay 3H, upon becoming deenergized, also opens the lighting circuit for lam-p G of signal 38 and closes the circuit for lamp R, passing from terminal B, through the back point of contact i ll of relay 3H, and lamp R. to terminal N.

When the train leaves block llb, relays DB and HB become energized by steady current of reverse polarity passing from terminal B, through the front point of contact 2i of relay 38R, Windings of relays DB and HB, contact 26 of relay I TR, and the front point of contact I 9 of relay 3SR to terminal N. With relays DB and HB thus energized by current of reverse polarity, the contacts of relay H'B will be closed at their front points, and the contacts of relay DB will be closed at their back points. Relay BP will therefore now be energized b a circuit passing from terminal B, through the front point of contact 26 of relay HB, back point of contact 21 of relay DB, and the winding of relay BP in multiple with condenser 28 to terminal N. With relays BP and HB thus energized, lamp Y of signal IS is steadily lighted by a circuit passing from terminal B, through the front point of contact 29 of relay BP, front point of contact 3| of relay I-lIB, back point of contact 30 of relay DB, and lamp Y of signal IS to terminal N.

When the train passes signal 5S, causing relay 5TB to become deenergized, relay 5H becomes deenergized because of the opening of contact 9 of relay 5TR. Lamp R of signal 58 therefore becomes lighted by a circuit which is similar to the circuit previously'traced for lamp R of signal 3S.

When the train leaves block b-(Z, relay 3H becomes energized by current of reverse polarity passing from terminal B, through the back point of contact I5 of rela 5H, winding of relay 3H, contact [4 of relay STR, contact l3 of relay A3TR, and the back point of contact I2 of relay 51-1 to terminal N. Relay 3H, upon becoming energized, opens its contact 34 at the back point in the stick circuit previously traced for relay 38R, causing relay 33R to become deenergized. With relay 3H energized by current of reverse polarity, relay SP is energized by a circuit passing from terminal B, through contact 16 of relay 3H, contact I! of relay 3H closed in the reverse position, and the winding of relay .3P to terminal N. With rela 3P energized, coding device CT becomes energized by a circuit passing from terminal B, through contact 25 of relay SP, and the winding of device CT to terminal N. y Relays DB and HB are now energized by coded current of reverse polarity passing from terminal B, through contact iii of relay 3H, contact 23 of code transmitter CT, front point of contact 22 of relay 3P, back point of contact 21 of relay 38R, windings of relays DB and HB, contact 20 of relay ITR, back point of contact IQ of relay 38R, front point of contact N3 of relay 3P, and contact 24 of device CT to terminal N. Relay BP is now energized by the second circuit traced for this relay, and, on account of being slow releasing, retains its front contact closed during the open periods of the front point of contact 26 of relay HB. The circuit previously traced for lamp Y of signal IS is now periodicall opened by the front point of contact 3| of relay HB, causing a flashing yellow aspect of signal IS for displaying the advance approach indication.

When the train proceeds far enough for relay 5H to become energized by current of normal or reverse polarity, lamp G or lamp Y of signal 5S becomes lighted, respectively, and relay 3H is again energized by current of normal polarity in the circuit first traced for this relay. Relay 3P will therefore be deenergized by the opening of contact [1 of relay 3H in its reverse position. With relay 3P deenergized, coding device CT will be deenergized. Relays DB and HB will now again be energized by current of normal polarity by the circuit first traced for these relays. Relay BP will therefore be energized by its circuit first traced, and lamp G of signal IS will again become lighted.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a trafilc directional signal control system for a stretch of railway track comprising two blocks over which traflic movements are regularly made in a given direction and also in the opposite direction, embodying track circuits including track relays for said blocks, for controlling a first or entering signal for governing trafiic movements in said given direction into said stretch and a second or intermediate signal for governing traffic movements in said given direction from the first block into the second block in advance of said entering signal and also a third or leaving signal for governin traific movements in said given direction out of said second block, the combination comprising, a signal relay responsive to traflic conditions for controlling said leaving signal to display a stop or 9, proceed indication, a polarized signal relay controlled by track circuit conditions in said secondblock and energized by current of normal or reverse polarity according as said leaving signal is controlled by said first signal relay to display a proceed or a stop indication, a trafiic'direction stick relay controlled to become energized if a train moving in said given direction enters said second block while said intermediate signal is controlled to display a proceed indication and to remain energized while said second block is occupied, code following control means for said entering signal, means controlled by said stick relay in th energized condition for energizing said code following control means by steady current of reverse polarity, means controlled by said-polarized signal relay for energizing said code following control means by coded current or by steady current of normal polarity according as said polarized signal relay is energized by current of reverse or of normal polarity respectively, and means controlled by said code following control means for controllin said engterin signal to display an approach or an advance approach or a, clear indication according as said code following control means is energized by steady current of reverse polarity or by coded current or by steady current of normal polarity respectively. p

2. In a traffic directional signal control system for a stretch of railway track comprising two blocks over which trafiic movements. are regularly made in a given direction and also in the opposite direction, for controlling signals for govace-awe:

eming, traffic movements in said: given direction including an entering signal for goveming'trafiic' movements into said stretch and an intermediate signal for governing trafiic. movements from. the first block in advance of said entering signal into the second. block and also. a leaving signal for governing trafiic movements out of said second block, the combination comprising, a; signal relay responsive to trafiic conditions in advance of said leaving signal for controlling said leaving. signal. to. display a proceed or a stop indication, a. polar ized signal relay energized by current of. normal or reverse polarity according as said leaving. signal is controlled by said. first signal relay to display a proceed. or a stop indication while said second block is unoccupied, a traffic'direction stick relay energized in response to a train entering said second block from said first block, code following control means for said entering signal controlled by front contacts of said stick relay to be energized by steady current of reverse polarity and controlled by reverse and normal contacts of. said polarized signal relay to be energized by coded current or by steady current of normal polarity respectively, and means controlled by said code following control means for controlling said entering signal to display an approach or an advance pproach or a clear indication according as said code following control means is energized by steady current of reverse polarity or by coded current or by steady current of normal polarity respectively.

3. In a traffic directional signal control system for a stretch of railway track comprising, two

blocks over which trafiic movements are regularly made ina given direction and also in. the opposite direction, for controlling signals: for governing tramc movements in said given direction including an entering signal for governing traffic movements into said stretchaand an intermediate signal for governing traffic movements from the first block in advance of said entering'signal, into the second block and also a. leaving signal for. governing traffic movements out of said second block, the combination comprising, means responsive to traflic conditions in advancerof'said leaving signal for controlling said leaving signal to display av proceed or-astop indication, a. traffic direction stick relay energized in response to a train entering said second block from said first block, code following control means for said entering signal comprising a given polar biasedLcode following relay and a second polar biased relay connected in opposed relation to each: other so that said second polar biased relay will close its front contacts in response to only current of normal polarity and said given polar biased code following relay will close its front contacts in response to only current of reverse polarity, means. controlled by said stick relay in its energized con-- dition for energizing said code. following control means by steady current of reverse polarity if said first block is unoccupied, means controlled by said controlling means for said leaving signal if said stretch of track is unoccupied for energizing said code following control means by coded current of reverse polarity if said leaving signal is controlled to indicate stop and for energizing said code following control means by steady current of normal polarity if said leaving signal is controlled to display a proceed indication, and means controlled by said code following control means for controlling said entering signal to display an approach or an advance approach or a clear indication according as said code following F 81 control means is energizedby steady current of reverse polarity or by coded current of reverse polarity or by steady current of normal polarity respectively.

4. In a traflic directional signal control system for a stretch of railway track comprising two blocks over which traffic movements are regularly made in a given direction and also in the opposite direction, for controlling signals for governing traffic movements in said given direction including an entering signal for governing trafllc movements into said stretch and an intermediate signal for governing trafiic movements from the first block in advance of said entering signal into the second block and also a leaving signal for governing traflic movements out of said second block, the combination comprising, means responsive to traffic conditions in advance of said leaving signal for controlling said leaving signal to display a proceed or a stop indication, a traflic direction stick relay energized in response to a train entering said second block from said first front and a reverse polar contact of said polarized signal relay, a coding device controlled by a front contact of said repeater relay, code following control means for said entering signal, means controlled by front contacts of said traflic direction stick relay for energizing said code follow-- ing control means by steady current of reverse polarity, means controlled by front contacts of said repeater relay and said coding device for energizing said code following control means by coded current of reverse polarity, means controlled by front and normal polar contacts of said polarized signal relay for energizing said code following control means by steady current of normal polarity, and means controlled by said code following control means for controlling said entering signal to display an approach or an advance approach or a clear indication according as said code following control means is energized by steady current of reverse polarity or by coded current or by steady current of normal polarity respectively.

5. In a traific directional signal control system for a stretch of railway track comprising two blocks over which trafiic movements are regularly made in a. given direction and also in the opposite direction, for controlling signals for governing traffic movements in said given direction including an enterin signal for governing traffic movements into said stretch and an intermediate signal for governing traflic movements from the first block in advance of said entering signal into the second block and also a leaving signal for governing tralnc movements out of said second block, the combination comprising, means responsive to traflic conditions in advance of said leaving signal for controlling said leaving signal to display a proceed or a stop indication, a traffic direction stick relay energized in response to a train entering said second block from said first block, two polar biased code following relays connected in series with each other but in opposed relation so that one of said polar biased relays will close its front contacts in response to current of a given polarity and the other polar biased relay will close its front contacts in response to current of the opposite polarity, means controlled by said stick relay in its energized condition for energizing said polar biased relays by steady current of said opposite polarity, means controlled by said controlling means for said leaving signal if said stretch of track is unoccupied for energizing said polar biased relays by coded current of said opposite polarity if said leaving signal is controlled to indicate stop and for energizing said polar biased relays by current of said given polarity if said leaving signal is controlled to display a proceed indication, and means controlled by said polar biased relays for controlling said entering signal to display an approach indication and an advance approach indication and also a clear indication as well as a stop indication.

6. In a traffic directional signal control system for a stretch of railway track comprising two blocks over which traflic movements are regularly made in a given direction and also in the opposite direction, for controlling signals for governing trafjc movements in said given direction including an entering signal for governing traiiic movements into said stretch and an intermediate signal for governing trafiic movements from the first block in advance of said entering signal into the second block and also a leaving signal for governing trafilc movements out of said second block, the combination comprising, means responsive to trafiic conditions in advance of said leaving signal for controlling said leaving signal to display a proceed or a stop indication, a traffic direction stick relay energized in response to a train entering said second block from said first block, two polar biased code following relays connected in series with each other but in opposed relation so that one of said polar biased relays will close its front contacts in response to current of a given polarity and the other polar biased relay will close its front contacts in response to current of the opposite polarity, means controlled by said stick relay in its energized condition for energizing said polar biased relays by steady current of said opposite polarity, a polarized signal relay, means controlled by said controlling means for said leaving signal if said second block is unoccupied for energizing said polarized signal relay by current of normal or reverse polarity according as said leaving signal is controlled to display a proceed or a stop indication, means controlled by a reverse polar contact of said polarized signal relay if said stretch of track is unoccupied for energizing said polar biased relays by periodically varied current of said opposite polarity, means controlled by a normal polar contact o said polarized signal relay if said stretch of track is unoccupied for energizing said polar biased relays by current of said given polarity, and means controlled by said polar biased relays for controlling said entering signal to display a steady yellow aspect and a flashing yellow aspect and also a green aspect and a red aspect.

WILLIAM H. CLAUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Number Young et al Sept. 29, 1942 

